I"ve been in a huge battle with my RO unit and the water its producing. I've changed all filters and new membrane and new DI. I'm getting 0.00 TDS and still getting a reading of 0.04 phosphates with the expensive hanna photometer. how is this happening? and what can I do to get that last bit of phosphates out of my top off and water change water. It's causing hair algae and cyano in two tanks. my rodi unit is a water general. I know they aren't considered top of the line, but I replaced all filters with good filters from Bulk reef Supply. any info would be appreciated.